Physical Science Mid-term Exam 2022

Front

What is a chemical change?

Back

A chemical change is a process where substances combine or break apart to form new substances, such as grilling a hamburger.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture that is evenly mixed throughout, such as coffee or vinegar.

Front

What is the atomic number of an element?

Back

The atomic number of an element is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the mass number of an atom?

Back

The mass number is the total number of protons and neutrons in an atom's nucleus.

Front

What is an independent variable in an experiment?

Back

The independent variable is the variable that is purposely changed or manipulated in an experiment.

Front

What is a dependent variable in an experiment?

Back

The dependent variable is the variable that is measured or observed in response to changes in the independent variable.

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a mixture that is not evenly mixed, where different components can be seen, such as salad.

Front

What is a pure substance?

Back

A pure substance is a material that has a constant composition and consistent properties, such as water or gold.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond together, such as water (H2O).

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.